The details: If your non-human support creature growls, has a habit of threatening to bite, or lunges at other passengers — you can't board with it, writes the Chicago Tribune's Lauren Zumbach.

• Those descriptions don't seem to fit all goats, lizards or spiders, but they are banned as well.
• Among permitted animals: miniature horses, such as the one in the photo above, as long as it can fit into a kennel underneath your seat and you pay its $125 fare.

Situational awareness: I have seen goats, sheep and chickens aboard flights in Afghanistan, but never in the U.S., Europe or elsewhere in Asia. Since Kabul is not on American's routes, I asked the airline whether people really travel with goats or miniature horses.

"While not common, these are things we have seen on American Airlines." American Airlines spokesman Ross Feinstein

More guidelines for your next trip:

• What animals can do on American: Sit in your lap as long as they are smaller than a 2-year-old child.
• What they can't do: Have their own seat or eat from your tray.